It has been a decade of quite spectacular triumph and devastating failure for the custodians of Africa's rhinos.

For the first time in several decades the overall number of white and black rhino has gone up rather than down, thanks to a determined rearguard action and a few frontal assaults by conservationists.

The good news is that there are now almost 4 000 black rhinos compared to the 2 600 which survived 10 years ago.

The white rhino has fared even better, with the overall population almost doubling from a total of 8 400 10 years ago, to almost 14 500 individuals today.

That translates into an annual growth rate of almost 7 percent for the white rhino and about 4,5 percent for the black rhino.

Yet it's still not a very rosy picture, considering that well over 62 000 black rhinos were slaughtered by horn poachers in the four decades that ended in the early 1990s.

And the bad news is that two subspecies of rhino have almost certainly become extinct over the past five years.

The northern white rhino - an animal that once roamed large swaths of central Africa - was slaughtered so extensively that 10 years ago just 25 of these animals were left in the Garamba national park on the north-east tip of the Democratic Republic of Congo.

Two years ago, an extensive search of the park revealed just four survivors. While they may have a remote chance of survival as individuals they are no longer a viable breeding population and this subspecies seems to have no future.

Then there is the western black rhino which once grazed the savannas between west and central Africa.

Two years ago, a survey of the last known population in Cameroon failed to find any evidence of these rhinos.

According to African rhino specialist George Kampamba, none of these animals is left over in captivity either, so the sub-species can now be presumed extinct.

Kampamba was among several rhino experts from across the continent who gathered in Pongola last week to celebrate the 10th anniversary of the African Rhino Programme, a concerted protection effort funded by the Swiss-based conservation group WWF.

Taye Teferi, conservation director for WWF in east Africa, summed it up this way: "We have made a good start - but we are not there yet."

Although WWF has been helping to fund rhino protection campaigns since the early 1960s, the African Rhino Programme was launched in 1997 to devise a more focused approach to ward off the very real threat of extinction for both species.

"In the 1970s and 1980s the main approach was to keep the bad guys out, using guns."

But programme leaders realised that while good security was vital, it was not enough to rely on a defensive strategy alone.

Teferi uses the analogy of a soccer team.

"You can have the best defenders at Manchester United - but unless you go on the attack sometimes, you will never score."

If rhinos were to survive and expand it was also imperative to protect and increase their living space.

And some hard choices also had to be made about withdrawing from certain rhino conservation projects which were not working. Simply put, WWF pulled out to avoid throwing good money after bad - especially in a funding environment where rhino conservation was gradually slipping off the agenda to make way for other pressing green concerns such as climate change and water pollution.

Martin Brooks, the Pietermaritzburg-based chairperson of the African Rhino Specialist Group, says that in the long run, spending scarce resources on protecting small and isolated groups of rhino would not make a significant contribution to the overall survival of the species.

Former Natal Parks Board vet Jacques Flamand also gave an overview of a novel project to expand the living range of KwaZulu-Natal's black rhino population.

Rather than keeping all the eggs in a few baskets, the project is planning to spread the eggs out and hopefully get rhinos to lay more eggs in more spacious surroundings.

Flamand said that over the past six years, nearly 70 black rhino had been removed from the Hluhluwe-Imfolosi, Ithala and Mkhuze game reserves and relocated to private and community-owned game reserves around the province.

While the 70 founder animals will remain the property of Ezemvelo KZN Wildlife, 50 percent of the calves they produce will become the property of their new custodians.

Flamand said the project aimed to increase the total black rhino population in KZN to 1 000 animals from the present level of nearly 500.

An indirect success of the project is that the breeding rate of black rhinos has since increased at Ithala and Mkhuze - though for reasons which are not yet clear, the growth rate of black rhinos at Hluhluwe-Imfolozi Park has declined.

Kampamba notes that more adult bulls are killed in fights and fewer calves born when there is not enough living space - and therefore the failure to breed because of overstocking is as much a loss to the species as the loss of a rhino through poaching.

At a continental level, the next step for the African Rhino Programme is to expand support to other African countries. So far, the main focus had been on South Africa, Namibia, Kenya and Zimbabwe.

During the next 10 years, the challenge is to work more closely with governments and local communities in Botswana, Malawi, Mozambique, Tanzania and Zambia.